A Clinical Guide to Chronic Pain

A Clinical Guide to Chronic Pain

Author: Thornton Trainor-Manuel | BNatMed | Naturopath and Medical Herbalist 

 

This Phytobrief includes discussions on:

Herbs: Devil's claw • Turmeric • Boswellia • Ginger • Willow bark • Andrographis • Kava • Passionflower • Saw palmetto • Chamomile • Arnica • Pukatea • Kawakawa

Nutritional: Omega-3 • Vitamin D • B vitamins • CoQ10 • Selenium • Anti-inflammatory diets

Lifestyle: Managing sleep • Physical activity • Stress and mind-body

 

Pain is something everyone goes through.  Whether it's a paper cut, something more serious like a broken bone or a health condition like arthritis.  For most people, pain is temporary.  It signals that something is wrong, helps protect us and then fades as healing occurs.  But for some people, pain doesn't go away when it's supposed to.  Instead, it becomes part of daily life, affecting how movement, sleep, work and general living feel.1 

Chronic pain is one of the main reasons people struggle with disability and have a lower quality of life, and it puts pressure on healthcare systems.  Because of this, being able to understand and manage chronic pain of clients is crucial for healthcare professionals.2,3     

Chronic pain is generally considered pain that lasts longer than three months.  In contrast, acute pain is short-term and often results from injury, inflammation or illness.  But pain extends beyond what's happening in the body.  It's a personal experience, both sensory and emotional, and sometimes the amount of pain someone feels doesn't match with how much tissue damage there is.  Pain may also stick around after the original injury has healed.  This is because pain is shaped by factors, such as how nerves function, how sensitive tissue is, what we expect, the situation we're in and how the brain processes it.2,3 

People often talk about pain in terms of how it works in the body.  There are a few main types: nociceptive, neuropathic and nociplastic pain.  These aren't always completely separate but can be experienced simultaneously.  Nociceptive pain happens when pain receptors (nociceptors) are activated by actual or possible tissue damage.  Neuropathic pain is more about problems with the nerves themselves.  Nociplastic pain occurs when altered nociception contributes to pain without clear evidence that tissue damage or a somatosensory lesion fully accounts for the pain.3,4  Pain also extends beyond biology.  There's also a biopsychosocial way of looking at it, which means our bodies, minds, emotions, relationships and habits, all play a part in how we feel pain, how much it affects us and how we recover.  Stress, mood, past trauma, poor sleep and certain habits can all make pain feel worse or harder to manage.4,5 

Many different aspects can make someone more likely to develop chronic pain.  These include age, sex, overall health, stress, life circumstances and the kind of support or environment someone has around them.4,5 

Clinical presentation and diagnostic framework  

When someone presents with chronic pain, the first thing a healthcare provider usually does is try to understand the circumstances, what's going on and figure out what kind of pain it is.  Chronic pain can be the main problem on its own, which is considered primary pain, or it can be connected to another illness or injury, which is considered secondary pain.  Understanding this helps guide what happens next, what kind of treatment to try and whether to refer the client to a specialist.  It's important to remember that things like age, stress or life circumstances are just pieces of the puzzle, not guaranteed causes.  In practice, these factors help health professionals consider how someone's biology, emotions, sleep, social life, work and past experiences with health, may impact their pain and how they're coping.3,5 

Chronic primary pain syndromes include:  

  • A chronic and widespread kind of pain, such as fibromyalgia.    
  • Complex regional pain syndrome.  
  • A chronic primary headache or orofacial pain.    
  • Chronic primary visceral pain.    
  • Chronic primary musculoskeletal pain, for example chronic primary low-back pain.5  

Chronic secondary pain syndromes include:  

  • The pain linked to cancer or its treatment.    
  • Postsurgical or post-traumatic pain.  
  • Neuropathic pain.  
  • A secondary headache or pain in the mouth and face.  
  • Visceral pain.    
  • Conditions of the musculoskeletal system that are related to inflammation or involve structural changes.5  

When trying to understand a client's pain, it's helpful to look at: where the pain is, when it started, how long it's been there, how often it comes and goes, how strong it feels, what makes it better or worse and whether there are other symptoms happening at the same time.  It's also important to know about past diagnoses, tests or treatments and how the client responded to them.1 

Sometimes health professionals use pain scales to get a sense of how intense the pain feels.  These scales help to track pain over time and give insight into the person’s subjective experience.  But it's not just about the pain itself or the number someone scores; it's also about how it affects movement, sleep, work, daily life, mood and the ability to connect with others.3,5 

Sometimes, a physical exam or more tests are needed, especially if there are signs that something else might be also occurring.  It's a good idea to review what has already been done, like past diagnoses, scans or treatments, so nothing important gets missed or repeated.  There are also certain warning signs, like unexplained weight loss, a history of cancer, serious injuries, new nerve problems or changes in bowel or bladder habits, that mean a health professional should take a closer look.5 

Pain management principles   

Pain can have different causes and show up in different ways, and because each person has their own goals and health situation, there isn't just one solution in its treatment.  Treatment may have different aims.  It might be about reducing pain, helping someone sleep better, making it easier to move, getting back to work or daily activities, supporting emotional health, or simply improving quality of life.  While less pain is a good thing, it's also important to consider whether someone can do more of what matters to them, making flexible, person-centred and adjustable plans the best option.1,5  Simply, masking pain is unlikely the better long-term solution. 

Medications used for pain management include non-opioid analgesics, NSAIDs, antidepressants, anticonvulsants, muscle relaxants, antispasmodics, corticosteroids or opioids.2,5  Some clients with chronic pain are on more than one medication, which means that special attention must be paid to possible herb-drug interactions, contraindications and cumulative adverse effects.1  

Chronic pain often goes hand in hand with stress, anxiety, depression and trouble sleeping.  Not sleeping well can affect how someone feels and functions, and it can even make pain feel worse or harder to cope with.  Sleep problems and chronic pain feed each other, creating a spiralling issue.1 

Supportive interventions for pain management  

What is most effective varies depending on the type of pain, the underlying diagnosis, medication use, other health conditions, pregnancy or breastfeeding and how the client has responded to previous treatments.  These factors should be considered when identifying the treatment plan.1 

Herbal interventions  

Devil’s claw (Harpagophytum procumbens)

Devil's claw helps with musculoskeletal pain, especially in cases like osteoarthritis or chronic low-back pain.  Some clinical studies suggest that certain Devil’s claw preparations can offer relief from symptoms, but the research has used a variety of preparations, doses and standardisations, making it difficult to compare products directly.  Harpagoside is one of the main compounds thought to contribute to its anti-inflammatory effects.  Laboratory studies suggest that Devil’s claw may influence several inflammatory pathways, such as COX-2, nuclear factor-kappa B, pro-inflammatory cytokines and oxidative stress.  To caution this, these findings are from preclinical laboratory research.1,6 

In short-term studies, Devil’s claw is usually well tolerated, though some people do experience digestive side effects like indigestion or stomach pain.  It’s best to be cautious if someone has a history of peptic ulcers or significant digestive issues and be mindful that there is limited information on its long-term safety.1,6 

Dosage: Root 1:2, 25% ethanol, 15-80 mL weekly dose, 1,071-5,714 mg daily dose dried herb equivalent. 

Turmeric (Curcuma longa)

Turmeric is often used for its anti-inflammatory properties, and there is some evidence that it may help reduce pain and improve function, particularly in osteoarthritis.  Curcuminoids, the active compounds in turmeric, are known to affect several inflammatory mediators and signalling pathways, including COX, LOX, nuclear factor-kappa B, inflammatory cytokines and inducible nitric oxide synthase.  Systematic reviews and meta-analyses have found that curcumin/curcuminoid extracts can improve pain, function and stiffness compared to placebo, especially in people with osteoarthritis.7,8 

Dosage: Rhizome 1:1, 45% ethanol, 35-90 mL weekly tincture dose, 5,000-12,857 mg daily dose dried herb equivalent.  

Boswellia (Boswellia serrata)

Boswellia may help with osteoarthritis and other types of inflammatory musculoskeletal pain.  The active compounds, known as boswellic acids (including AKBA), are believed to have anti-inflammatory effects through pathways like 5-lipoxygenase and nuclear factor-kappa B.  Some clinical trials and meta-analyses suggest that certain Boswellia extracts can reduce pain, stiffness and limitations in function for people with osteoarthritis.  That said, results are not always consistent between different preparations.1,9 

Ginger (Zingiber officinale)

Ginger contains compounds such as gingerols and shogaols, which have anti-inflammatory and antioxidant properties that may contribute to its potential analgesic effects.  Some clinical evidence suggests that ginger can modestly reduce pain and disability in osteoarthritis, and there is also some support for its use in easing pain related to primary dysmenorrhoea.10,11,12 

Ginger can cause gastrointestinal irritation for some people.  High supplemental doses may have possible interactions with medicines that affect bleeding risk.10 

Dosage: Rhizome 1:2, 90% ethanol, 5-15 mL weekly dose, 357-1,070 mg daily dose dried herb equivalent. 

Willow bark (Salix alba)

Willow bark contains phenolic compounds, including salicin, that help contribute to its analgesic and anti-inflammatory effects.  Clinical evidence shows Willow bark extracts are helpful in chronic low-back pain, while evidence for other musculoskeletal conditions is less consistent.13,14  

Because willow bark contains salicylates, it should be used with caution or avoided by people with salicylate or aspirin hypersensitivity, peptic ulcer disease, a significant bleeding risk or those taking medications that increase bleeding risk.  If someone is already using NSAIDs or other salicylate-containing medicines, it’s important to review this carefully.13,14 

Dosage: Bark 1:2, 45% ethanol, 20-50 mL weekly dose, 1,430-4286 mg daily dose dried herb equivalent.

Andrographis (Andrographis paniculata)

Andrographis may be helpful for mild-to-moderate knee osteoarthritis.  In one randomised placebo-controlled trial, a standardised andrographolide-containing extract led to improvements in pain, stiffness, physical function and quality of life over 12 weeks compared with placebo.  Andrographis can cause allergic reactions in some people.  The TGA recently removed Andrographis from the permitted ingredient list due to severe allergic reactions in 287 anaphylactic cases and one death.1,15,16  

Dosage: Herb 1:2, 45% ethanol, 20-40 mL weekly dose, 1,430-3,571 mg daily dose dried herb equivalent. 

Kava (Piper methysticum)

Kava may be helpful when anxiety, stress-related muscle tension or sleep disturbance are adding to the burden of chronic pain.  Kavalactones affect several central nervous system pathways, including GABAergic signalling, which may help explain their calming and sedative effects.  However, the evidence for kava as a direct pain reliever in chronic pain is limited, so it’s probably best considered as an adjunct, aimed more at psychological or sleep-related contributors to pain rather than pain intensity itself.1,17,18 

Kava has been linked to rare but potentially serious liver toxicity.  For this reason, people with liver disease or abnormal liver function should only use kava with appropriate oversight.  It’s also important to consider possible additive sedation and herb-drug interactions before using kava, particularly with other CNS depressants.1,17 

Dosage: Root 1:2, 60% ethanol, 20-60 mL weekly dose, 1,429-4,286 mg daily dose dried herb equivalent. 

Passionflower (Passiflora incarnata)

Passionflower contains flavonoids, alkaloids and other compounds that may influence GABAergic activity in the central nervous system.  It may be helpful when anxiety, psychological stress, sleep disturbance, restlessness or muscle tension are contributing to chronic pain.  The clinical evidence is stronger for anxiety and sleep disturbance than for direct pain relief, and the studies so far have been limited by small sample sizes and differences in the preparations used.19,20 

Passionflower may have additive sedative effects if combined with other medicines or herbs that cause drowsiness, so it’s a good idea to review any concurrent medicines or supplements before using it.19,20 

Dosage: Herb 1:2, 45% ethanol, 15-40 mL weekly dose, 1,071-2,857 mg daily dose dried herb equivalent. 

Saw palmetto (Serenoa repens)

Saw palmetto may be helpful in chronic prostatitis or chronic pelvic pain syndrome (CP/CPPS).  One randomised controlled trial found improvements in pain and overall symptom scores compared with placebo for that condition.1,21 

Dosage: Berry 1:2, 60% ethanol, 15-30 mL weekly dose, 1,071-2,143 mg daily dose dried herb equivalent. 

Chamomile (Matricaria recutita)

Chamomile may be helpful for pain related to primary dysmenorrhoea.  A systematic review of seven clinical trials found evidence that chamomile reduced pain and menstrual bleeding across the included trials.1,22 

Dosage: Flower 1:2, 50% ethanol, 20-60 mL weekly dose,1,428-4,285 mg daily dose dried herb equivalent.  

Arnica (Arnica montana)

Arnica may be useful topically for acute musculoskeletal pain, bruising, swelling and some post-traumatic or postoperative situations.  The clinical evidence is mixed and varies a lot depending on the preparation, and much of the research involves topical or homeopathic products, which are not equivalent.  Oral use of concentrated Arnica preparations is not recommended due to toxicity concerns.23,24 

A note on CBD and THC for pain 

Cannabinoid-based medicines can offer pain relief in some chronic pain conditions, particularly neuropathic pain, depending on the cannabinoid composition and preparation.  Current evidence is more supportive of THC-containing products than CBD alone, since oral CBD by itself has not shown significant reductions in pain intensity compared with placebo.  THC-containing preparations may also increase dizziness, sedation and nausea, and it’s important to consider potential drug interactions, cognitive effects and dependence risk.25 

Natives for pain support 

Pukatea (Laurelia novae-zelandiae)

Pukatea has a long history of use in rongoā Māori for pain, particularly neuralgia and toothache.  Historical accounts describe the inner bark being chewed or prepared as a pulp or decoction, for painful conditions.  The bark contains several alkaloids, including pukateine, which was investigated historically for its analgesic properties.  Later pharmacological research identified dopaminergic activity and antioxidant effects of isolated pukateine in experimental models, providing further scientific interest in this constituent.  However, these studies do not establish the clinical efficacy of pukatea preparations for chronic pain in humans.  Pukatea remains an important traditional analgesic with a history of use in Māori medicine and clinical herbal practice, although modern clinical trials are lacking.26-29 

Kawakawa (Piper excelsum)

Kawakawa is an important rākau in rongoā Māori and has traditionally been used for a range of painful conditions, including toothache, rheumatism and other aches and pains.  Its leaves contain a diverse range of bioactive compounds, including amides such as pellitorine, which has been proposed to contribute to its numbing properties.  Laboratory research has also investigated Kawakawa's potential anti-inflammatory activity.  A 2024 study analysed blood samples from 26 healthy adults following Kawakawa tea consumption and found changes in several inflammation-related microRNAs and gene-expression markers, including IL-6 and IL-8.  However, the study examined short-term molecular responses rather than pain outcomes and the significance of these changes for clinical pain management remains unknown.  Kawakawa is therefore an interesting native plant with traditional analgesic use and emerging pharmacological research.30-32 

Nutrient interventions  

Omega-3 

Omega-3 fatty acids, particularly EPA and DHA, have anti-inflammatory effects and could be useful combined with other treatments for cases of inflammatory pain.  Fatty fish such as salmon, mackerel, anchovies, sardines and herring are good sources of EPA and DHA, while flaxseeds, chia seeds and walnuts mainly contain ALA.  Algae can provide DHA and, depending on the way it is prepared, can contain EPA.  Some clinical evidence for omega-3 supplementation involves inflammatory conditions such as rheumatoid arthritis, and some systematic reviews indicate that higher doses might have a greater effect.  In most clinical studies, doses are based on the total amount of EPA and DHA, not on the overall quantity of fish oil.33,34 

Vitamin D 

Vitamin D is fat-soluble with anti-inflammatory properties.  It is important for both controlling pain and immune function.  It occurs in foods such as oily fish, fortified products, full-fat milk, butter and eggs.  Vitamin D is also produced in the body when skin is exposed to the sun.  Supplementation should be guided by factors such as baseline vitamin D status, body size, dietary intake, sun exposure and clinical need.35,36 

B vitamins 

B vitamins, particularly B1, B6 and B12, are essential for proper nervous system function and may be useful in the management of neuropathic pain.  Since deficiencies in vitamin B12 and other B vitamins can lead to neurological issues, suspected nutritional deficiencies should be assessed and addressed.  The evidence regarding the use of B-vitamin supplements as a general remedy for neuropathic pain is uncertain, and therefore any treatment should be adapted to the condition and vitamin in question.  Caution should also be exercised with respect to vitamin B6, as long-term use of high doses can in fact result in sensory neuropathy.  B vitamins occur in a great variety of foods, such as meat, fish, eggs, dairy products, legumes, leafy vegetables, whole grains, nuts and seeds.1,37 

CoQ10 

CoQ10 (Coenzyme Q10) is a naturally produced fat-soluble antioxidant involved in the generation of energy in the mitochondria.  Early clinical studies indicate that CoQ10 may be of some benefit as an additional treatment for conditions such as fibromyalgia and rheumatoid arthritis, with improvements in pain and other symptoms reported in some studies.  Yet the evidence remains limited, mainly due to the small number of participants in the studies and variations across supplement formulations.  The compound is found in foods that contain fat such as eggs, fatty fish, nuts, avocado and poultry.1,38 

Selenium 

Selenium is a trace element necessary for antioxidant defence, thyroid and immune function.  Although there is some early clinical evidence indicating that taking selenium supplements could help to reduce pain in rheumatoid arthritis, the evidence for its use in other kinds of chronic or neuropathic pain is less substantial.  When considering supplements, it is necessary to consider both the amount obtained through the diet and the existing selenium level, since excessive intake over a long period can be harmful.  The element can be found in protein-rich foods such as seafood, meat, poultry and Brazil nuts.1,39,40 

Anti-inflammatory diets 

Anti-inflammatory diets focus on eating mostly minimally processed foods high in fibre, vegetables, fruit, legumes, whole grains and antioxidants, while limiting highly processed foods and excessive saturated fat.  The Mediterranean diet is the most widely studied example, and the DASH diet shares many of these features.  There is evidence that dietary changes can help improve pain and related outcomes for people with chronic pain, though the benefits depend on both the specific diet and the pain condition.1,41 

Lifestyle and self-management strategies 

Lifestyle changes matter for chronic pain because they can improve sleep quality, inflammation, stress levels, tolerance for movement, mood and a person's ability to do daily activities.  Introduce any changes or interventions at a realistic, manageable pace, considering the individual's current pain level, capabilities and daily needs.1  

Managing sleep 

Managing sleep is important for pain treatments when dealing with chronic pain, since sleep difficulties and pain tend to make each other worse.  Bad sleep can increase pain sensitivity, make it harder to cope and reduce a person's ability to do activities.  In contrast, ongoing pain can disrupt sleep.  When evaluating sleep, consider duration and quality and whether insomnia or other sleep disorders are present.42,43  Useful sleep-support methods include sticking to a regular sleep schedule, adopting good sleep habits, gentle relaxation or stretching exercises in the evening or referring someone for cognitive behavioural therapy for insomnia (CBT-I) if necessary.1,44  In many instances, a nighttime herbal tonic may also be worth considering to reset the sleep process.1  

Physical activity 

Physical activity can reduce chronic pain severity, help maintain physical function and generally improve wellbeing.  Choose exercise types that suit the individual's current abilities, symptoms, confidence level and goals, and adjust gradually over time.  Pacing is particularly useful here, as it can break the cycle of overdoing it and then needing long periods of rest, while also enabling slow, steady progress towards what matters most to the person.  Focusing on mobility and stability can be especially beneficial, as both can significantly impact quality of life.  Depending on what seems appropriate, a client may find walking, swimming, cycling, resistance training, yoga, tai chi or working with a physiotherapist helpful.1,45  

Stress and mind-body 

Stress and mind-body methods are particularly helpful when living with chronic pain, as pain and psychological stress tend to reinforce one another.  Prolonged pain can affect the body's stress systems, including the HPA axis and cortisol regulation.  While psychological factors can influence the severity of pain, the limitations it causes, how one copes with it and its impact on quality of life, this does not imply that the pain is entirely in the mind.  Mindfulness-based approaches may benefit both pain and psychological wellbeing.  Such approaches can include mindfulness, meditation, gentle yoga, relaxation or other mind-body practices.  In the case of a client who is experiencing anxiety, depression, trauma, emotional distress or difficulty in coping with pain, it can be helpful to involve a psychologist or a mental health professional.  For chronic primary pain, cognitive behavioural therapy (CBT) and acceptance and commitment therapy (ACT) have evidence to support them.1,47  

Chronic pain management works best when it begins with a comprehensive assessment, sets realistic goals, empowers the individual to take control of their care and identifies treatments that address their specific needs.  The most effective approaches are tailored to the individual, reviewed regularly and adjusted as circumstances change.  Those changes may involve pain, functioning, sleep, mood, medication, safety or whatever is most important to the client.1 


For more information, read the following related articles:

Phytotherapy for Pain: NZ Natives Phytotherapy for Pain | Phytomed 

The Pain Effect The Pain Effect | Phytomed Blog 

Sleep and Nociceptive Pain Sleep and Nociceptive Pain-Phytomed 

Omega-3 vs Omega-6: Reframing the Inflammatory Debate Omega-3 vs Omega-6: Reframing the Inflammatory Debate | Phytomed NZ 

 

References 

  1. Sarris J, Wardle J.  Clinical naturopathy: an evidence-based guide to practice.  2nd ed. Chatswood (NSW): Elsevier; 2014. 
  2. Shetty A, Delanerolle G, Cavalini H, Deng C, Yang X, Boyd A, et al.  A systematic review and network meta-analysis of pharmaceutical interventions used to manage chronic pain.  Sci Rep. 2024;14(1):1621.  https://doi.org/10.1038/s41598-023-49761-3  
  3. Treede RD, Rief W, Barke A, Aziz Q, Bennett MI, Benoliel R, et al.  Chronic pain as a symptom or a disease: the IASP Classification of Chronic Pain for the International Classification of Diseases (ICD-11).  Pain. 2019;160(1):19-27.  https://doi.org/10.1097/j.pain.0000000000001384    
  4. Karcz M, Abd-Elsayed A, Chakravarthy K, Aman MM, Strand N, Malinowski MN, et al.  Pathophysiology of pain and mechanisms of neuromodulation: a narrative review (A Neuron Project).  J Pain Res. 2024;17:3757-3790.  https://doi.org/10.2147/JPR.S475351  
  5. Rahman S, Kidwai A, Rakhamimova E, Elias M, Caldwell W, Bergese SD.  Clinical diagnosis and treatment of chronic pain.  Diagnostics. 2023;13(24):3689.  https://doi.org/10.3390/diagnostics13243689    
  6. Hong JY, Lee J, Kim H, Kim H, Jeon WJ, Yeo C, et al.  Harpagophytum procumbens in musculoskeletal disorders: current evidence and comparison with NSAIDs.  Front Pharmacol. 2026;17:1839470.  https://doi.org/10.3389/fphar.2026.1839470   
  7. Bideshki MV, Jourabchi-Ghadim N, Radkhah N, Behzadi M, Asemani S, Jamilian P, et al.  The efficacy of curcumin in relieving osteoarthritis: a meta-analysis of meta-analyses.  Phytother Res. 2024;38(6):2875-2891.  https://doi.org/10.1002/ptr.8153    
  8. Hidayat R, Parlindungan F, Nisa JI, Mahendra AI, Indika MI, Efendi C.  Efficacy of Curcuma longa in relieving pain symptoms of knee osteoarthritis patients: a systematic review and meta-analysis of clinical trials.  J Rheum Dis. 2025;32(1):17-29.  https://doi.org/10.4078/jrd.2024.0062  
  9. Dalmonte T, Andreani G, Rudelli C, Isani G.  Efficacy of extracts of oleogum resin of Boswellia in the treatment of knee osteoarthritis: a systematic review and meta-analysis.  Phytother Res. 2024;38(12):5672-5689.  https://doi.org/10.1002/ptr.8336    
  10. Terry R, Posadzki P, Watson LK, Ernst E.  The use of ginger (Zingiber officinale) for the treatment of pain: a systematic review of clinical trials.  Pain Med. 2011;12(12):1808-1818.  https://doi.org/10.1111/j.1526-4637.2011.01261.x   
  11. Moshfeghinia R, Salmanpour N, Ghoshouni H, Gharedaghi H, Zare R, Cramer H, et al.  Ginger for pain management in primary dysmenorrhea: a systematic review and meta-analysis.  J Integr Complement Med. 2024;30(11):1016-1030.  https://doi.org/10.1089/jicm.2023.0799   
  12. Bartels EM, Folmer VN, Bliddal H, Altman RD, Juhl C, Tarp S, et al.  Efficacy and safety of ginger in osteoarthritis patients: a meta-analysis of randomized placebo-controlled trials.  Osteoarthritis Cartilage. 2015;23(1):13-21.  https://doi.org/10.1016/j.joca.2014.09.024  
  13. Shara M, Stohs SJ.  Efficacy and safety of white willow bark (Salix alba) extracts.  Phytother Res. 2015;29(8):1112-1116.  https://doi.org/10.1002/ptr.5377 
  14. Lin CR, Tsai SHL, Wang C, Lee CL, Hung SW, Ting YT, et al.  Willow bark (Salix spp.) used for pain relief in arthritis: a meta-analysis of randomized controlled trials.  Life (Basel). 2023;13(10):2058.  https://doi.org/10.3390/life13102058  
  15. Hancke JL, Srivastav S, Cáceres DD, Burgos RA.  A double-blind, randomized, placebo-controlled study to assess the efficacy of Andrographis paniculata standardized extract (ParActin®) on pain reduction in subjects with knee osteoarthritis.  Phytother Res. 2019;33(5):1469-1479.  https://doi.org/10.1002/ptr.6339  
  16. Goods T.  Andrographis paniculata (Andrographis) and anaphylaxis-updated safety review and supplementary report [Internet].  Therapeutic Goods Administration (TGA). 2026 [cited 2026 Sept 29].  Available from: https://www.tga.gov.au/products/medicines/listed-medicines/monitoring-and-compliance/compliance-and-education-listed-medicines/andrographis-paniculata-andrographis-and-anaphylaxis-updated-safety-review-and-supplementary-report  
  17. Teschke R.  Kava hepatotoxicity-a clinical review.  Ann Hepatol. 2010;9(3):251-265. 
  18. Faustino TT, Almeida RB, Andreatini R.  Plantas medicinais no tratamento do transtorno de ansiedade generalizada: uma revisão dos estudos clínicos controlados [Medicinal plants for the treatment of generalized anxiety disorder: a review of controlled clinical studies].  Rev Bras Psiquiatr. 2010;32(4):429-436.  https://doi:10.1590/S1516-44462010005000026   
  19. Janda K, Wojtkowska K, Jakubczyk K, Antoniewicz J, Skonieczna-Żydecka K.  Passiflora incarnata in neuropsychiatric disorders-a systematic review.  Nutrients. 2020;12(12):3894.  https://doi:10.3390/nu12123894  
  20. Lee J, Jung HY, Lee SI, Choi JH, Kim SG.  Effects of Passiflora incarnata Linnaeus on polysomnographic sleep parameters in subjects with insomnia disorder: a double-blind randomized placebo-controlled study.  Int Clin Psychopharmacol. 2020;35(1):29-35.  https://doi:10.1097/YIC.0000000000000291  
  21. Zhang K, Guo RQ, Chen SW, Chen B, Xue XB, Chen S, et al.  The efficacy and safety of Serenoa repens extract for the treatment of patients with chronic prostatitis/chronic pelvic pain syndrome: a multicenter, randomized, double-blind, placebo-controlled trial.  World J Urol. 2021;39(9):3489-3495.  https://doi:10.1007/s00345-020-03577-2  
  22. Niazi A, Moradi M.  The effect of chamomile on pain and menstrual bleeding in primary dysmenorrhea: a systematic review.  Int J Community Based Nurs Midwifery. 2021;9(3):174-186.  https://doi:10.30476/ijcbnm.2021.87219.1417  
  23. Toma CC, Marrelli M, Puticiu M, Conforti F, Statti G.  Effects of Arnica phytotherapeutic and homeopathic formulations on traumatic injuries and inflammatory conditions: a systematic review.  Plants (Basel). 2024;13(21):3112.  https://doi:10.3390/plants13213112  
  24. Adkison JD, Bauer DW, Chang T.  The effect of topical arnica on muscle pain.  Ann Pharmacother. 2010;44(10):1579-1584.  https://doi:10.1345/aph.1P071  
  25. Chou R, Ahmed AY, Dana T, Morasco BJ, Bougatsos C, Fu R, et al.  Living systematic review on cannabis and other plant-based treatments for chronic pain: 2024 update.  Rockville (MD): Agency for Healthcare Research and Quality (US); 2024. 
  26. Xie L, Wang X, Chu J, He X, Bao J, Xi Y, et al.  Effects of omega-3 fatty acids on chronic pain: a systematic review and meta-analysis.  Front Med (Lausanne). 2025;12:1654661.  https://doi:10.3389/fmed.2025.1654661  
  27. Manaaki Whenua-Landcare Research.  Laurelia novae-zelandiae: Pukatea.  Ngā Rauropi Whakaoranga [Internet].  Lincoln: Manaaki Whenua; updated 2023 Oct 30 [cited 2026 Oct 13].  Available from: https://rauropiwhakaoranga.landcareresearch.co.nz/names/09dcad2f-3ee8-41e3-8a57-cca22c0fe9c8 
  28. Fogg WS.  The pharmacological action of pukateine.  J Pharmacol Exp Ther. 1935;54(2):167-187. 
  29. Dajas-Bailador FA, Asencio M, Bonilla C, Scorza MC, Echeverry C, Reyes-Parada M, et al.  Dopaminergic pharmacology and antioxidant properties of pukateine, a natural product lead for the design of agents increasing dopamine neurotransmission.  Gen Pharmacol. 1999;32(3):373-379.  https://doi.org/10.1016/S0306-3623(98)00210-9 
  30. Jayaprakash R, Ramzan F, Miles-Chan JL, Foster M, Mithen RF, Pook C.  Exploring the chemical space of kawakawa leaf (Piper excelsum).  Nutrients. 2022;14(23):5168.  https://doi.org/10.3390/nu14235168 
  31. Tautuiaki S, Gojer J, Jayaprakash R, Sharma P, Pook C, Foster M, et al.  Anti-inflammatory effects of kawakawa (Piper excelsum): an integrative mRNA-miRNA approach.  Food Sci Nutr. 2024;12(11):8858-8869.  https://doi.org/10.1002/fsn3.4450 
  32. Health New Zealand.  Rongoā Māori [Internet].  Wellington: Health New Zealand | Te Whatu Ora; [cited 2026 Oct 13].  Available from: https://www.healthnz.govt.nz/health-topics/tests-and-treatments/rongoa-maori 
  33. Kostoglou-Athanassiou I, Athanassiou L, Athanassiou P.  The effect of omega-3 fatty acids on rheumatoid arthritis.  Mediterr J Rheumatol. 2020;31(2):190-194.  https://doi:10.31138/mjr.31.2.190  
  34. Habib AM, Nagi K, Thillaiappan NB, Sukumaran V, Akhtar S.  Vitamin D and its potential interplay with pain signalling pathways.  Front Immunol. 2020;11:820.  https://doi:10.3389/fimmu.2020.00820  
  35. Alonso-Pérez JL, Martínez-Pérez I, Romero-Morales C, Abuín-Porras V, López-Bueno R, Rossettini G, et al.  Relationship between serum vitamin D levels and chronic musculoskeletal pain in adults: a systematic review.  Nutrients. 2024;16(23):4061.  https://doi:10.3390/nu16234061  
  36. Páez-Hurtado AM, Calderón-Ospina CA, Nava-Mesa MO.  Mechanisms of action of vitamin B1 (thiamine), B6 (pyridoxine) and B12 (cobalamin) in pain: a narrative review.  Nutr Neurosci. 2023;26(3):235-253.  https://doi:10.1080/1028415X.2022.2034242  
  37. Freire de Carvalho J, Skare T.  Coenzyme Q10 supplementation in rheumatic diseases: a systematic review.  Clin Nutr ESPEN. 2024;59:63-69.  https://doi:10.1016/j.clnesp.2023.11.016  
  38. Nazıroğlu M, Öz A, Yıldızhan K.  Selenium and neurological diseases: focus on peripheral pain and TRP channels.  Curr Neuropharmacol. 2020;18(6):501-517.  https://doi:10.2174/1570159X18666200106152631  
  39. Long M, Xu S, Tie S, Dong S, Liang H, Wang J, et al.  Effect of selenium supplementation on inflammatory markers and joint symptoms in patients with rheumatoid arthritis: a meta-analysis and systematic review.  J Trace Elem Med Biol. 2025;91:127695.  https://doi:10.1016/j.jtemb.2025.127695  
  40. Field R, Pourkazemi F, Turton J, Rooney K.  Dietary interventions are beneficial for patients with chronic pain: a systematic review with meta-analysis.  Pain Med. 2021;22(3):694-714.  https://doi:10.1093/pm/pnaa378  
  41. Limongi F, Cilona L, Guberti E, Volpe M, Maggi S, Onder G, et al.  Efficacy of Mediterranean diet in musculoskeletal disorders: a systematic review and meta-analysis for primary and tertiary prevention featured in the Italian National Guidelines "La Dieta Mediterranea".  Nutrition. 2026;142:112950.  https://doi:10.1016/j.nut.2025.112950  
  42. Goossens Z, Van Stallen A, Vermuyten J, De Deyne M, Rice D, Runge N, et al.  Day-to-day associations between pain intensity and sleep outcomes in an adult chronic musculoskeletal pain population: a systematic review.  Sleep Med Rev. 2025;79:102013.  https://doi:10.1016/j.smrv.2024.102013  
  43. Nijs J, Mairesse O, Neu D, Leysen L, Danneels L, Cagnie B, et al.  Sleep disturbances in chronic pain: neurobiology, assessment and treatment in physical therapist practice.  Phys Ther. 2018;98(5):325-335.  https://doi:10.1093/ptj/pzy020  
  44. Selvanathan J, Pham C, Nagappa M, Peng PWH, Englesakis M, Espie CA, et al.  Cognitive behavioral therapy for insomnia in patients with chronic pain: a systematic review and meta-analysis of randomized controlled trials.  Sleep Med Rev. 2021;60:101460.  https://doi:10.1016/j.smrv.2021.101460  
  45. Geneen LJ, Moore RA, Clarke C, Martin D, Colvin LA, Smith BH.  Physical activity and exercise for chronic pain in adults: an overview of Cochrane Reviews.  Cochrane Database Syst Rev. 2017;4(4):CD011279.  https://doi:10.1002/14651858.CD011279.pub3   
  46. Timmers I, Quaedflieg CWEM, Hsu C, Heathcote LC, Rovnaghi CR, Simons LE.  The interaction between stress and chronic pain through the lens of threat learning.  Neurosci Biobehav Rev. 2019;107:641-655.  https://doi:10.1016/j.neubiorev.2019.10.007  
  47. Zhu M, Wong SY, Zhong CC, Zeng Y, Xie L, Lee EK, et al.  Which type and dosage of mindfulness-based interventions are most effective for chronic pain? A systematic review and network meta-analysis.  J Psychosom Res. 2025;191:112061.  https://doi:10.1016/j.jpsychores.2025.112061 
Back to blog